We found the fix already.
1. Download and install the Security Update for Windows XP (KB926255) file.
Download Here: it http://forum.mygame.ph/downloads/Window ... 86-ENU.exe
2. After installing the file, restart your PC.
You may now play SF without your PC restarting.
Please let us know if you are still having the restart problem after installing the file.
We will ask the developers if its possible to include this file to our installer / client.
Again, we apologize for the inconvenience and Thank you!